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Pre-registration of username Signature Structure

To authorize the preRegistrationUsername operation, the user (_user) must generate a cryptographic signature compliant with the EIP-191 standard.

The signature is created by signing a precisely formatted string message derived from the pre-registration details.

Signed Message Format​

The message is constructed by concatenating the following components as strings, separated by commas (,):

string.concat(
    "b667c80b",
    ",",
    AdvancedStrings.bytes32ToString(_hashUsername),
    ",",
    Strings.toString(_mateNameServiceNonce)
)

1. MNS Pre-registration Identifier (Hex String):*

  • Value: b667c80b
  • Purpose: A specific identifier used within the EIP-191 framework to distinguish MNS username pre-registration messages from other types of signed messages in the system.

2. Username Hash (String):

  • Value: The result of AdvancedStrings.bytes32ToString(_hashUsername).
  • Purpose: The string representation of the bytes32 hash commitment being pre-registered. This hash is derived from the user's chosen username and their secret clowNumber.

3. MNS Nonce (String):

  • Value: The result of Strings.toString(_nonce).
  • Purpose: The string representation of the user's nonce specific to the MNS contract (mateNameServiceNonce). This prevents replay attacks for pre-registration actions initiated by the _user.
tip
  • addressToString converts an address to a lowercase string
  • Strings.toString converts a number to a string
  • AdvancedStrings.bytes32ToString(bytes32 _input) converts a bytes32 value into its lowercase hexadecimal string representation

Hash Username Structure​

For pre-registration of a username, users must provide a hash of the username. The hash is calculated using SHA3-256 with the following structure:

keccak256(abi.encodePacked(_username, _clowNumber));

Where:

  • _username is the desired username
  • _clowNumber is the key number of the username that will be used in the registrationUsername function